地铁列车荷载激励下综合交通枢纽车站站房结构的振动响应

Vibration Response of Station Structure of Comprehensive Transportation Hub Station under Subway Train Load Excitations

对大型综合交通枢纽车站南昌西站进行现场实测,研究地铁2号线列车运行荷载的振动传播规律及频率分布特点,分析综合交通枢纽车站站房结构的局部振动规律及频谱响应规律。研究结果表明:在地铁列车运行荷载的作用下,站房结构的振动响应随距离振源高度的增大呈指数衰减;不同结构层楼板的振动特性与振动主频均有所差异,随着距离振源高度的增大,列车进出站引起的楼板振动响应由高频逐渐向低频移动,其中60 Hz频率附近的振动响应衰减最慢;在5～40 Hz的低频范围内,换乘层、候车厅楼板层的振动响应大于站台层的振动响应;不同跨度的楼板具有不同的频率响应特性,楼板的跨度越大,结构越柔;候车厅楼板区域的振动响应,传播距离每增大12 m,振动加速度振级平均衰减2～4 dB,在距离轨道中心线30～48 m的区域出现振动放大区,振动放大响应对轴线处的影响较大。

Field measurement was carried out at Nanchang West Station,a large-scale comprehensive transportation hub station.The vibration propagation laws and frequency distribution characteristics of train operation load on Metro Line 2 were studied,and the local vibration laws and spectrum response laws of station structures in comprehensive transportation hub station were analyzed.Research results show that under the action of the operation load of subway trains,the vibration response of the station structure decreases exponentially with the increase of the height of vibration source.The vibration characteristics of different structural floor slabs are different from the main frequency of vibration.As the height from the vibration source increases,the vibration response of the floor caused by the train entering and leaving the station is gradually shifted from high frequency to low frequency,and the attenuation of vibration response is the slowest near the frequency of 60 Hz.In the low frequency range of 5~40 Hz,the vibration response of the transfer floor and the waiting hall floor is greater than that of platform floor.The floor slabs of different spans have different frequency response characteristics,and the larger the span of the floor slab,the more flexible the structure.The propagation distance of the vibration response in the floor area of waiting hall increases by 12 m,and the vibration acceleration level is attenuated by an average of 2~4 dB.The vibration amplification area appears in the area 30~48 m away from the center line of the track.The vibration amplification response has a great influence on the axis.